Hewetson A, Chilton B S
Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
Biol Reprod. 1997 Aug;57(2):468-77. doi: 10.1095/biolreprod57.2.468.
The microenvironment of the endocervix is regulated by secretory (> 10-15 x 10(6) Da) and cell-surface (< or = 1 x 10(6) Da) mucins. A survey with antisense and sense (control) oligonucleotides for eight epithelial mucin genes revealed that only MUC1, an anti-adhesive protein believed to modulate immune function and the only transmembrane mucin for which molecular probes exist, is expressed in the rabbit cervix. pMUC7, a 500-base pair cDNA probe to the tandem repeat domain of human MUC1, was used to clone the cDNA for the rabbit homologue. Although the GC-rich tandem repeat of rabbit Muc1 had only 40% sequence identity with its human counterpart, its transmembrane domain and cytoplasmic tail maintained 93% sequence identity with the same regions of human MUC1. Detection of restriction length polymorphisms confirmed the Lagomorpha Muc1 gene, like the human, is polymorphic. Temporal expression of Muc1 transcripts (2.4 kilobases) correlated closely with epithelial differentiation in the cervix. However, compared with the adult cervix, uterine endometrium expressed the highest levels of Muc1. In the endometrium, Muc1 was increased (p < 0.0004) by progesterone and returned to estrous levels by treatment with estrogen. Muc1 levels in the cervix were unaffected by ovarian steroids, confirming tissue-specific regulation of Muc1 in the lower reproductive tract.
子宫颈内膜的微环境由分泌型（分子量> 10 - 15×10⁶Da）和细胞表面型（分子量≤1×10⁶Da）粘蛋白调节。一项针对8种上皮粘蛋白基因的反义及正义（对照）寡核苷酸的研究表明，在兔子宫颈中仅表达MUC1，它是一种据信可调节免疫功能的抗粘附蛋白，也是唯一存在分子探针的跨膜粘蛋白。用针对人MUC1串联重复结构域的500个碱基对的cDNA探针pMUC7来克隆兔同源物的cDNA。尽管兔Muc1富含GC的串联重复序列与其人类对应序列的序列同一性仅为40%，但其跨膜结构域和细胞质尾与人类MUC1相同区域的序列同一性保持在93%。限制性片段长度多态性检测证实，兔形目动物的Muc1基因与人类基因一样具有多态性。Muc1转录本（2.4千碱基）的时间表达与子宫颈上皮分化密切相关。然而，与成年子宫颈相比，子宫内膜中Muc1的表达水平最高。在子宫内膜中，孕酮可使Muc1增加（p < 0.0004），而用雌激素处理后则恢复到发情期水平。子宫颈中的Muc1水平不受卵巢类固醇的影响，这证实了下生殖道中Muc1的组织特异性调节。
